<script lang="ts" setup>
  import type { PropType } from 'vue'
  import { ref, unref, watch, watchEffect } from 'vue'
  import { Cascader } from 'ant-design-vue'
  import { get, omit } from 'lodash-es'
  import { LoadingOutlined } from '@ant-design/icons-vue'
  import { propTypes } from '/@/utils/propTypes'
  import { isFunction } from '/@/utils/is'
  import { useRuleFormItem } from '/@/hooks/component/useFormItem'
  import { useI18n } from '/@/hooks/web/useI18n'

  interface Option {
    value: string
    label: string
    loading?: boolean
    isLeaf?: boolean
    children?: Option[]
  }

  defineOptions({ name: 'ApiCascader' })

  const props = defineProps({
    value: {
      type: Array,
    },
    api: {
      type: Function as PropType<(arg?: Recordable<any>) => Promise<Option[]>>,
      default: null,
    },
    numberToString: propTypes.bool.def(false),
    resultField: propTypes.string.def(''),
    labelField: propTypes.string.def('label'),
    valueField: propTypes.string.def('value'),
    childrenField: propTypes.string.def('children'),
    apiParamKey: propTypes.string.def('parentCode'),
    immediate: propTypes.bool.def(true),
    // init fetch params
    initFetchParams: {
      type: Object as PropType<Recordable<any>>,
      default: () => ({}),
    },
    // 是否有下级，默认是
    isLeaf: {
      type: Function as PropType<(arg: Recordable<any>) => boolean>,
      default: null,
    },
    displayRenderArray: {
      type: Array,
    },
  })

  const emit = defineEmits(['change', 'defaultChange'])
  const apiData = ref<any[]>([])
  const options = ref<Option[]>([])
  const loading = ref<boolean>(false)
  const emitData = ref<any[]>([])
  const isFirstLoad = ref(true)
  const { t } = useI18n()
  // Embedded in the form, just use the hook binding to perform form verification
  const [state]: any[] = useRuleFormItem(props, 'value', 'change', emitData)

  watch(
    apiData,
    (data) => {
      const opts = generatorOptions(data)
      options.value = opts
    },
    { deep: true },
  )

  function generatorOptions(options: any[]): Option[] {
    const { labelField, valueField, numberToString, childrenField, isLeaf } = props
    return options.reduce((prev, next: Recordable<any>) => {
      if (next) {
        const value = next[valueField]
        const item = {
          ...omit(next, [labelField, valueField]),
          label: next[labelField],
          value: numberToString ? `${value}` : value,
          isLeaf: isLeaf && typeof isLeaf === 'function' ? isLeaf(next) : false,
        }
        const children = Reflect.get(next, childrenField)
        if (children) Reflect.set(item, childrenField, generatorOptions(children))

        prev.push(item)
      }
      return prev
    }, [] as Option[])
  }

  async function initialFetch() {
    const api = props.api
    if (!api || !isFunction(api)) return
    apiData.value = []
    loading.value = true
    try {
      const res = await api(props.initFetchParams)
      if (Array.isArray(res)) {
        apiData.value = res
        return
      }
      if (props.resultField) apiData.value = get(res, props.resultField) || []
    } catch (error) {
      console.warn(error)
    } finally {
      loading.value = false
    }
  }

  async function loadData(selectedOptions: Option[]) {
    const targetOption = selectedOptions[selectedOptions.length - 1]
    targetOption.loading = true

    const api = props.api
    if (!api || !isFunction(api)) return
    try {
      const res = await api({
        [props.apiParamKey]: Reflect.get(targetOption, 'value'),
      })
      if (Array.isArray(res)) {
        const children = generatorOptions(res)
        targetOption.children = children
        return
      }
      if (props.resultField) {
        const children = generatorOptions(get(res, props.resultField) || [])
        targetOption.children = children
      }
    } catch (e) {
      console.error(e)
    } finally {
      targetOption.loading = false
    }
  }

  watchEffect(() => {
    props.immediate && initialFetch()
  })

  watch(
    () => props.initFetchParams,
    () => {
      !unref(isFirstLoad) && initialFetch()
    },
    { deep: true },
  )

  function handleChange(keys, args) {
    emitData.value = args
    emit('defaultChange', keys, args)
  }

  function handleRenderDisplay({ labels, selectedOptions }) {
    if (unref(emitData).length === selectedOptions.length) return labels.join(' / ')

    if (props.displayRenderArray) return props.displayRenderArray.join(' / ')

    return ''
  }
</script>

<template>
  <Cascader
    v-model:value="state"
    :options="options"
    :load-data="loadData"
    change-on-select
    :display-render="handleRenderDisplay"
    @change="handleChange"
  >
    <template v-if="loading" #suffixIcon>
      <LoadingOutlined spin />
    </template>
    <template v-if="loading" #notFoundContent>
      <span>
        <LoadingOutlined spin class="mr-1" />
        {{ t('component.form.apiSelectNotFound') }}
      </span>
    </template>
  </Cascader>
</template>
